drm/radeon/kms/legacy: set common regs to sane value

The DDX and radeonfb always set these regs to a sane value.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/r420.c b/drivers/gpu/drm/radeon/r420.c
index d72f0439b..162c390 100644
--- a/drivers/gpu/drm/radeon/r420.c
+++ b/drivers/gpu/drm/radeon/r420.c
@@ -169,6 +169,9 @@
 {
 	int r;
 
+	/* set common regs */
+	r100_set_common_regs(rdev);
+	/* program mc */
 	r300_mc_program(rdev);
 	/* Resume clock */
 	r420_clock_resume(rdev);